my @first_symbol_range = @second_symbol_range = ( 'a'..'z' );
my @fird_symbol_range = ( 0..9 );
for my $first_symbol (@first_symbol_range) {
    for my $second_symbol (@second_symbol_range) {
        for my $fird_symbol (@fird_symbol_range) {
            my $word = $first_symbol . $second_symbol . $fird_symbol;
        }
    }
}